Which of the following hypothetical electronic configurations for a ground-state atom violates Hund' — Atomic Structure Chemistry Question

💡 Solution & Explanation

Option A places two electrons in the $2p_x$ orbital before singly occupying the degenerate $2p_y$ and $2p_z$ orbitals. This violates Hund's rule. However, since no orbital holds more than two electrons, it obeys Pauli's principle, and the lower energy $2s$ is filled before $2p$, obeying Aufbau. Option B violates Pauli's principle ($3$ electrons in $2s$). Option C is the correct, rule-abiding ground state for Nitrogen. Option D violates the Aufbau principle because the $2s$ subshell is not completely filled before electrons enter the $2p$ subshell.